The Blade Whisperer Returns with Morten Handberg

Morten Handberg, Principal Consultant at Wind Power LAB, joins the
show to discuss the many variables within wind turbine blades that
operators may not be aware of. From design to materials and
operation, understanding your blades is crucial to making informed
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show? Email us! Welcome to Uptime Spotlight, shining light on
wind. Energy's brightest innovators. This is the progress Powering
tomorrow. Allen Hall: Morten, welcome back to the
program.  Morten Handberg: Thank you so much, Allen. It's
fantastic to be back. It's, uh, I really, really happy to be back
on the show to discuss blades with you guys.  Allen
Hall: So you're a resident blade whisperer, and we wanted to
talk about the differences between types of blades even within the
same manufacturer, because I think there's a lot of
misunderstanding if I buy a specific OEM turbine that I'm getting
the same design all the time, or even just the same basic materials
are that are used. That's not the case anymore.  Morten
Handberg: No, I mean, there's always been variations. Uh, so
the B 90 is a very good example because initially was, was released
with, uh, with the, with the glass fiber spark
cap. [00:01:00] But at later iterations it was, then they
then switched it to carbon fiber for, for, for larger, for larger
turbines, for higher rated power. But it, it, but it sort of gave
that you were not a hundred percent sure. When you initially looked
at it, was this actually a ca a glass fiber, uh, beam or a carbon
fiber was only when you started to learn the integral, you know,
what, what to read in, in the naming convention that you could
understand it. But it caused a little confusion about, you know,
I'm looking at glass fiber blade or, or a carbon fiber blade. So
it's been there for a while, but we're seeing it more and more
pronounced with, um. Uh, OEMs changing to signs, uh, or OEMs
merging together, but keeping their integral design for, for, for
various purposes. And then for the, for the, for the people, not
in, uh, not in the loop or not looking behind the curtain. They
don't, you don't know, know, know the difference. So I think it's
really important that we, that we sort of highlight some of those
things to make it easier for people to, to, to know, to know this.
Allen Hall: There was a generational
change. [00:02:00] Uh, even in the 1.5 megawatt class.
There were some blades that were fiberglass and then they, there
was a trend to move to carbon fiber to make them lighter, but then
the designers got better and started putting fiberglass in, where
now you have 70 meter blades that are fiberglass worth 35 meter
blades, may have had carbon. Yeah, it's hard to keep up with
it.  Morten Handberg: You know, it's really difficult to
know. I mean, for, for, for the longer blades, it's becoming more
and more pronounced that they will be, uh, there will be carbon
fiber reinforced. But a good, uh, example of where it doesn't
really apply is actually with, uh, with Siemens cesa. Because if
you look at Siemens, Cade said, you know, it's, it's Siemens, uh,
the original OEM Siemens at the original OEM Cade that merged.
Quite a few years back, but you know, we still see the very sharp,
uh, difference between the two different designs because whenever
you install a Siemens Esso turbine offshore, it's the Siemens
integral blade, it will. And, and they kept
that, [00:03:00] uh, and that blade is produced in one
cast, it's called the Integral Blade because that's their inherited
design. And there are no adhesive bond blinds in that. Uh, so all
laminated is consolidated. It's all cast in one go, and then
whatever kings and small, uh, defects there, then repaired on
factory before they ship offshore. These are pure glass fiber plate
that has not changed at all. So that's sort of the, uh, how do you
say, uh, the one that, that, uh, that is outside the norm that we
see today. But the Gaza part of it, they, they've kept for onshore
purposes, they kept their design using, uh, adhered shells or
adhered bond lines. So they would have two, uh, share webs and then
two shells, uh, that are then, that are then, then, uh, glued
together, uh, at the bond lines, on the share, on the trading edge,
and on the leading edge. With carbon re, re reinforcement. Um, so
that is a massive different design within
one [00:04:00] OEM and often when people say, well, we
have a problem with the Siemens commes blade, which one? Uh, so
then it's very, very important to understand, you know, what blade
type, you know, what, what, what turbine model it is because then
we can pretty easily drive it, or even for just know the wind farm
because. If it's offshore, we pretty much, you know, we can, we, we
know already. We just need to know the what, what, what size of
turbine is, and derive what blade type it is. Onshore becomes a bit
more pro problematic because then you need to know, you know, at
what, when was it erected, because then, you know, it can be both,
but. If you don't know, then it will just be presented as a Siemens
cesa. So it's really important to keep, uh, in check, uh, when,
when, when, when, when looking at that. So that's a, so that's a
very important distinction that, that we need, need to understand
when the child, when determining blade damages,  Allen
Hall: right, because the type of damage, the integral blade
would suffer really completely different than the sort of the ESA
bonded design. I was looking at blades in Oklahoma recently that
were integral from like a two megawatt machine, and it,
it [00:05:00] looks completely different when you walk up
to that blade. You can tell that it's cast in one piece. It's very
interesting to see, but that makes it, I think the, the thing about
those blades is that it's a little more manufacturing cost to, to
make 'em that way, but. They are, uh, tend to be a little more
rugged out in service, right?  Morten Handberg: Well,
they're, they're definitely heavier because of the, the
manufacturing process that they go through. Um, they're more
robust. We, I think we can, we can, we can see that from a track
record, uh, in general. Um, but they're, but the trade off is that
they are a lot, they're heavier. So that means that the, that the
components that are used in the Drivetrain Tower Foundation,
they're equally heavier. So you pay the price in the, uh, in the
cost of the turbine. But, uh, overall on the, on the mainland side,
we do see less, at least some structural damages and if something
really bad happens, so, uh, the trailing edge more often, not it's
kept to the, to the tip or on that part of the trailing edge. So,
so, uh, so [00:06:00] the, the, the blade structure keeps
together better, um, because of this consolidation of the
laminates. Allen Hall: Right, and the, the traditional ESA
design, I'll call it, has been a bonded design for a long time. The
issue with bond lines is there is no peel ply stoppage, so there's
no fasteners in it, in case it starts to come apart, it'll continue
to peel, and that's what we typically call a banana peel when it
really goes bad. The blade splits in two. Once it starts, it really
doesn't have a way to stop. And I think that's why inspection is so
important on those bonded blades. Right?  Morten
Handberg: Yeah. Actually, 1, 1, 1 1, 1, 1 small thing. Uh,
peel ply is actually something that's used in laminate production
to, uh, to you apply it when you're casting, you laminate typically
for repair. Then when you peel it off. The surface is fresh and
clean, and then you can, you can continue working it, adding more,
more mobilely or, or new coating. So it removes some, uh,
lamination or some grinding process that will otherwise be needed,
has no structural purpose in it, [00:07:00] uh, just to
kill that myth of, but you're right. Uh, when you have an adhere
blade for any, for any manufacturer, for any purpose. If you have
a, uh, if you have a deep bonding that starts, then it can, it can,
depending on the location, it can grow really fast because you
don't have the same consolidation. You do have some bike layers
that would add over, but it doesn't have the same integral strength
that you would see with the, uh, with the consolidated laminate.
Allen Hall: So that's a big difference. And if you're looking
at blades, and if you haven't. Looked inside of a hub and looked
inside the blade. You, you may not even know. And I think that does
happen to a lot of engineers that they, because they, they're
dealing with a thousand blades a lot of times the blade engineers,
it's crazy what they're asked to go do. You just can't know all the
details all the time. But just knowing these top level things can
really help you suss out like where to start. And, and, and even on
the inspection res regimes would on an integral blade type design,
are you doing different kinds of inspections than you would do on a
standard kind of. Mesa bonded up design?  Morten
Handberg: I would [00:08:00] say not actually. I
mean, you would still, you would still do, uh, you, you'll still do
internal inspections because, um, you can still have defect
developing. They would be, uh, slower, uh, growing in general, um,
compared to a, uh, to a more thin skin laminate, uh, type blade.
But, but the inspection methodology is, is more, less the same. You
would do an external inspection to check for lighting damages
wearing of, uh, coating. So erosion. Any kind of structural damage
in developing over the shell, uh, surfaces.